Questions Flashcards
Respiration is referred to as 2 processes…
internal and external respiration
How are the cardiovascular and skeletomuscular systems both critical to the physiology of external respiration?
- by itself, the respiratory system is a series of air-filled tubes and spaces
- the thoracic and abdominal muscles (and thoracic cage) produce movements for ventilation
- the pulmonary circuit brings blood to the lungs for oxygenation
What are the secondary functions of the respiratory system and explain their purpose. (there is 3)
- Protective Barrier:
-> Keeps foreign substances (microbes, viruses or pollutants) in the air from entering the body - Sensory:
-> Neurons in the nasal cavities detect volatile ‘odorants’ aka smells - Communication:
-> Airflow is manipulated to allow for the production of speech and other sounds
The respiratory system has an upper and lower track what are their functions?
Upper Tract Functions:
- air conditioning (and conduction)
- olfaction
- Sound articulation
Lower Tract Functions:
- air conduction
- phonation
- (external) preparation
The lower respiratory tract is divided into conducting and respiratory portions. Identify what is in each portion.
Conducting Portion:
- Larynx
- Trachea
- Bronchi (3 types)
-> 2 primary bronchi
-> 5 lobar bronchi
-> 19 segmental bronchi
- Bronchioles (3 types)
-> 10s of 1000s of terminal bronchioles
Respiratory Portion:
- pulmonary lobules (respiratory bronchioles and alveolar sacs)
By the terminal bronchioles, what does the respiratory epithelium no longer have? What happens?
mucous and ciliated cells
- mobile macrophages ( type of phagocytic WBC) take over the protective functions performed by mucus
what are respiratory surfaces covered with?
- are covered with an epithelium that is specialized for rapid gas exchange
Where does external respiration ONLY occur?
- alveoli
- the rest of the respiratory tract is simply pathways for air to flow within
where can gas exchange ONLY occur?
where the air is near the capillaries of the pulmonary circuit
What is the respiration challenge and solution?
Challenge:
respiration requires fresh air to reach the alveoli regularly… however, the respiratory tract is a passive structure which continues air but cannot propel it and there is only 1 way in and out of the tract
Solution:
the body has evolved a pump that creates pressure gradients to move air for pulmonary ventilation
During quiet breathing what muscles are active?
ONLY primary inspiratory muscles are active
Is exhalation passive or active?
passive
During quiet breathing what happens to the exhalation phases?
the exhalation phase simply involves the relaxation of inspiratory muscles and the elastic recoil of the thoracic cavity
What happens during active (or forced) breathing?
accessory inspiratory and expiratory muscles are recruited to amplify movements
How are skeletal muscles involved in respiration?
- the respiration movement depends on skeletal muscles, and this one somatic motor neurons
Where are the motor neurons’ innervation and other inspiratory and expiratory muscles found?
are found in the cervical and thoracic spinal cord
what does the respiratory cycle depend on?
on neural activity generated within the medulla
The rate and pattern of breathing movements are generated by?
activity in respiratory centres in the medulla
no medullary respiratory center activity = NO
NO BREATHING (DEAD)
What drives the breathing muscles?
respiratory center neurons make synapses on the spinal motor neurons that drive breathing muscles
What activates Metabolic respiratory reflexes?
are activated by chemoreceptors in elastic arteries and the medulla
In addition to affecting brainstem cardiovascular centres chemoreceptors also…and why?
stimulate medullary respiratory centres to increase respiratory relate and volume
When does recruiting accessory breathing muscle increase?
it increases the energy demands of respiratory movements, so these are usually only used when oxygen demand is high
How much effort does it take to inflate a lung?
- Resistance
-> how to detect
-> how does it affect the lungs
Resistance:
-> The person is unable to fully fill their lungs
-> Even at rest, the person has to do more work to achieve the same volume of air-inspired
-> detected in spirometry by reduced FVC (or TLC)
-> detect by examining a patient’s detect by examining a patient’s (forced) viral capacity (FVC)
-> is characterized by lower capacity for air across most measures of lung function
-> is the measurement of how much force is needed to make air flow through conducting pathways
-> The diameter of airway passages is a major determinant of the overall resistance (and bronchioles are the biggest contributors)
Volume Flowrate (mL/s) = F = (P1-P2)/R
Resistance to flow: R = (8nL)/pir^4